The present invention relates to a terminal cover of a circuit breaker such as a molded-case circuit breaker and an earth leakage breaker, and to an attaching structure of the cover.
In a circuit breaker, a terminal cover is provided for covering a terminal (a threaded terminal) on each of a power source side at one end and a load side at the other end of a main body case (a molded resin case) Accordingly, a live-part is not exposed, thereby preventing an electric shock accident. Patent Reference 1 has disclosed a circuit breaker in which a terminal cover is detachably attached onto a main body case, so that a press ring terminal is secured to a terminal by tightening a screw.
In the structure disclosed in Patent Reference 1, the terminal cover has an engaging hole in each of right and left side walls thereof. When the terminal cover is pushed into the main body case of the circuit breaker from above a terminal section, an engaging projection formed on, an outer surface of each side wall of the main body case is fitted into the engaging hole, so that the terminal cover is snap-fitted to the main body.
Patent Reference 1: Japanese Patent Publication (Kokai) No. 2003-257299
The terminal cover disclosed in Patent Reference 1 has the following disadvantages. The terminal cover is a one-way assembling system. That is, when the terminal cover is attached to the main body case, the terminal cover can be secured at a specific position simply by pressing the terminal cover into the main body case. However, when the terminal cover is detached, it is necessary to insert a tool such as a flat-tip screwdriver from a side into a gap between the main body case and the terminal cover to bend and open the terminal cover. Accordingly, it is difficult to detach the terminal cover at a site where a plurality of circuit breakers is mounted in line in a panel such as a switchboard.
In view of the problems described above, an object of the present invention is to provide a terminal cover of a circuit breaker in which the terminal cover can be easily attached to and detached from the main body case by a simple operation. With the terminal cover, when a press terminal is secured to a terminal by tightening a screw for connecting a cable, it is possible to completely cover the press terminal, so that a live-part is not exposed and a sufficient insulation distance from the press terminal is secured.
Further objects and advantages of, the invention will be apparent from the following description of the invention.